Objective: To compare zofenopril + hydrochlorothiazide (Z + H) vs. irbesartan + hydrochlorothiazide (I + H) efficacy on daytime SBP in elderly (>65 years) patients with isolated systolic hypertension (ISH), untreated or uncontrolled by a previous monotherapy.
Methods: After a 1-week run-in, 230 ISH patients (office SBP ≥ 140 mmHg and DBP < 90 mmHg + daytime SBP ≥ 135 mmHg and daytime DBP < 85 mmHg) were randomized double-blind to 18-week treatment with Z + H (30 + 12.5 mg) or I + H (150 + 12.5 mg) once daily, in an international, multicenter study. Z and I doses could be doubled after 6 and 12 weeks, and nitrendipine 20 mg added at 12 weeks in nonnormalized patients.
Results: In the full analysis set (n = 216) baseline-adjusted average (95% confidence interval) daytime SBP reductions after 6 weeks (primary study end point) were similar (P = 0.888) with Z + H [7.7 (10.7, 4.6) mmHg, n = 107] and I + H [7.9 (10.7, 5.0) mmHg, n = 109]. Daytime SBP reductions were sustained during the study, and larger (P = 0.028) with low-dose Z + H at study end [16.2 (20.0, 12.5) mmHg vs. 11.2 (14.4, 7.9) mmHg I + H]. Daytime SBP normalization (<135 mmHg) rate was similar under Z + H and I + H at 6 and 12 weeks, but more common under Z + H at 18 weeks (68.2 vs. 56.0%, P = 0.031). Both drugs equally reduced SBP in the last 6 h of the dosing interval and homogeneously reduced SBP throughout the 24 h. The proportion of patients reporting drug-related adverse events was low (Z + H: 4.4% vs. I + H: 6.0%; P = 0.574).
Conclusion: Elderly patients with ISH respond well to both low and high-dose Z or I combined with H.